Propulsion device



Dec. 21, 1965 A. P. SFREDDA 3,224,408

PROPULS ION DEVI CE Filed May 21, 1964 2 Sheets-Sheet 1 ifferf g w BY W ATTORN EY Dec. 21, 1965 A. P. SFREDDA 3,224,408

PROPULSION DEVICE Filed May 21, 1964 2 Sheets-Sheet 2 Z 4 45452 rald ATTORNEY United States Patent 3,224,408 PROPULSION DEVICE Albert P. Sfredrla, Bethlehem, Pa., assignor of fifty percent to George W. Downs, Collegeville, Pa. Filed May 21, 1964, Ser. No. 369,137 Claims. (Cl. 115l2) This invention relates generally to propulsion devices for vehicles, and this application is a continuation-inpart of my copending patent application Serial No. 171,215, filed February 5, 1962.

While the propulsion device or system disclosed herein has been primarily developed and employed in marine applications, and will be illustrated and described hereinafter with particular reference thereto, it is appreciated that the structure of the instant invention is well adapted for use in other than marine vehicles, and all applications of the instant invention are intended to be comprehended herein.

It is an important object of the present invention to provide a propulsion device of the reaction type which is highly efficient in operation and affords enhanced operational characteristics, such as ease and accuracy of controlability and responsiveness.

It is a further object of the present invention to provide a reaction-type propulsion device having the advantageous characteristics mentioned in the preceding paragraph, which is extremely simple in construction, requiring a minimum of moving parts, durable and reliable throughout a long useful life, and which can be economically manufactured, installed and maintained.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangernents of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

In the drawings:

FIGURE 1 is a top plan view showing a propulsion device of the present invention mounted at the stern of a boat, the device being partly broken away for clarity of understanding, and illustrating in phantom an optional position of operation;

FIGURE 2 is a sectional elevational view taken generally along the line 2-2 of FIGURE 1;

FIGURE 3 is a sectional plan view taken generally along the line 3-3 of FIGURE 2;

FIGURE 4 is a rear elevational View showing a slightly modified embodiment of marine propulsion unit constructed in accordance with the teachings of the present invention;

FIGURE 5 is a side elevational view showing the embodiment of FIGURE 4;

FIGURE 6 is a top plan view showing the apparatus in an open boat, and partly broken away for clarity;

FIGURE 7 is a sectional elevational view taken generally along the line 77 of FIGURE 6;

*lGURE 8 is a rear elevational view showing another slightlymodified embodiment of the present invention;

FIGURE 9 is a sectional plan view taken generally along the line 99 of FIGURE 8; and

FIGURE 10 is a sectional elevational View taken generally along the line Ill-10 of FIGURE 9.

Referring now more particularly to the drawings, and specifically to FIGURES 13 thereof, a marine vehicle boat is generally designated 20, only the stern section of the hull being shown. The boat hull includes a bottom 21, opposite sides 22, and a top or deck 23. The hull 2b is formed in its stern section with a recess or cham- 3,224,408 Patented Dec. 21, 1965 her 24 having a bottom wall 25 disposed generally horizontally at an elevation spaced between the hull bottom 21 and deck 23. The recess 24 is bounded by a front wall 26 upstanding from the forward edge of bottom wall 24, and side walls 27 upstanding from opposite sides of the bottom wall and extending from the front wall rearwardly to the transom 28 of the boat. Thus, the recess or chamber 24 opens rearwardly from the boat through the transom thereof.

Centrally of the recess 24, through the bottom wall 25 may be a thru opening 30 to the sea. In the region of the opening 30, the boat bottom may be recessed upward, as at 31.

Seated on the upper surface of bottom wall 25 is a generally fiat baseplate 32 having a central aperture 33 in registery with the bottom-wall opening 30. The baseplate 32 may be generally circular and provided about its periphery with an upstanding circumferential rib or flange 34. An annular retaining plate is seated on the upper surface of rib 34 and rigidly secured thereto, as by bolts 36. The retaining member or annular plate 35 extends radially inward beyond the rib 34 to spacedly overhang an outer portion of the basepla-te 32.

An enclosure or housing is generally designated and includes a generally flat lower portion 41 having a central thru opening 42 and rotatably seated on the baseplate 32. The opening 42 registers with the base plate opening 33 and hull opening 30, and a radially outstanding circumferential flange or lip 43 projects from the lower enclosure portion 41 beneath the overhang of retainer 35. The enclosure 40 is thus held on the baseplate 32 and constrained to rotative movement about a generally central and vertical axis.

The enclosure 40 further includes a generally horizontal top wall 45 spaced over the bottom portion 41, and a side wall 46 extending vertically between and partially about the peripheries of the lower portion 41 and top wall 45. More specifically, the enclosure side wall 46 extends approximately halfway around the circumference of the enclosure, generally the forward half thereof, so that the enclosure may be said to open rearwardly, as at 47. In particular, the enclosure opening 47 faces obliquely rearward in the normal straight-ahead position shown in FIGURES 1 and 3, for a purpose appearing presently. Located in the rearward enclosure opening 47 are a plurality of guide vanes 48 for directing flow in substantial parallelism rearwardly from the vessel, as will presently be more fully understood. In addition, side-wall extensions 49 and 50 extend from opposite ends of the enclosure side wall 46 and aid in the parallel direction of fluid.

Centrally within the enclosure 40 is a rotor generally designated 55. The rotor is of hollow construction and may include a hollow central region 56 and one or more radially extending, hollow spokes or tubes 57. The underside of the central rotor region 56 is formed with a thru opening 58 in alignment with the openings 42, 33 and 30 and thus communicating with the sea, to define an inlet passageway, as will appear presently. Extending across the vertically downwardly opening inlet passageway 58 may be a cup-shaped grille or screen 59 depending through the openings 42, 33 and 30.

The radially extending tubular spokes 57 may be of generally rectangular cross-sectional configuration, as illustrated, or other suitable configuration, and as illustrated each includes a bottom wall 60 extending radially outward from the inlet passageway 58, upstanding side walls 61 extending radially outward along opposite side edges of the bottom wall, and a top wall 62 extending radially outward from the top wall of central rotor region 56 and bridging the side walls 61. Thus, each tubular rotor spoke 57 opens at its radially inner end to the interior of the central rotor region 56, and has its outer end opening radially outward.

In practice, it may be advantageous to configure the tubular rotor spokes or arms to be of radially outwardly tapering or decreasing cross section for achieving greater discharge velocity of fluid. If desired, a wall of each rotor arm 57 may be provided with suitable expansile means to prevent its being clogged by solid material and serving to dislodge any article tending to effect clogging. Toward this end, one of the side walls 61 may include a resiliently deflectable sheet 63 anchored at its radially inner end, as by a fastener 64. Thus, the resilient sheet 63 operates as a leaf spring to open and expand its rotor arm for releasing a solid object from within the tapering arm.

Mounted on the upper side of enclosure top wall 45 may be suitable drive means 66, such as an internal combustion engine. A drive shaft 67 may depend rotatably through the upper enclosure wall 45 for fixed securement to the top wall of central rotor region 56. The shaft 67 is in alignment with the rotor 55 and inlet passageway 58 for effecting rotation of the rotor about the generally vertical axis of the shaft and inlet passageway.

Also carried by the enclosure 40 is a reversing scoop generally designated 70. The scoop 70 is shown in solid lines in FIGURES 1 and 2 as extending across and facing toward the rear enclosure opening 47, and includes at opposite ends a pair of forwardly extending arms 71 connected to the enclosure, as by horizontal pivot 72. In this manner, the scoop 70 is mounted for movement with the enclosure 40, and also for up-and-down swinging movement between the solid and phantom positions shown in FIGURE 2.

Suitable actuating means may be connected to the scoop 70, as by the outstanding arm 74 for positioning the scoop as desired. Also, the enclosure or housing 40 may be actuated in its rotative movement by any suitable means, say connected to an arm 75 projecting from the drive motor 66. Remote operation to efiect rotation of the housing or enclosure 40 about its vertical axis may be effected by cables 76 connected to the arm 75.

In operation, the drive motor 66 rotates its shaft 67 to rotate the rotor 55. The rotor arms 57 thus swing angularly about the vertical axis of shaft 67, as in the direction of arrows 77 in FIGURE 3. Water in the rotor arms 57 is centrifugally impelled outward through the discharge opening 47, thereby causing upward withdrawal of sea water through the strainer 59 and inlet passageway 58 for continued radially outward discharge through the outlet passageways defined by the rotor arms. As best seen in FIGURE 3, the open distal ends of the rotor arms 57 are closed as each rotor arm passes the enclosure side wall 46, and opened as each rotor arm passes the enclosure opening 47. The closure of the outlet passageways or arms 57 is caused by close proximity of the enclosure wall 46 to the ends of the arms. The fluid discharged through opening 47 is guided by vanes 48 and extensions 49 and 50 so as to exit from the opening 47 in substantially parallel flow. It is the reaction to this outlet flow that causes propulsion of the vehicle 20. The direction of liquid discharge may be selectively adjusted by rotating the enclosure 40, as through the actuating arm 75, to steer the vessel, while reversal of the vessel is caused by movement of scoop 70 into the path of liquid discharge to reverse the direction thereof.

In FIGURES 4-7 are shown a slightly modified embodiment of the instant invention, a water vehicle or boat there being generally designated a, the boat hull having a bottom 21a, upstanding sides 22a, and a transom 28a.

Within the stern section of the boat 20a, at laterally spaced locations therein are a pair of enclosures or housings 40a, each opening rearwardly, as at 47a through the transom 28a.

Also located in the stern may be suitable power means 66a, say between the housings 40a and having a pair of oppositely projecting drive shafts 67a each extending rotatably into a respective housing 40a. The power means 66a may consist of a single motor or engine having oppositely extending shafts, or a pair of back-to-back motors or engines.

Each hull side 22a may be recessed, as at 31a in the region of the adjacent housing 401:, and there provided with an inlet opening 30a having a covering grille or screen 59a. An inlet conduit 33a extends from each inlet opening 30a to the adjacent housing 40a and communicates with the central interior region thereof.

Located in each enclosure 40a is a hollow spoked rotor 55a, which may be essentially similar to the rotor 55 of the first-described embodiment. However, each rotor 55a is mounted for axial rotation about the horizontal axis of a respective shaft 67a. That is, the enclosures 40a are disposed generally vertically, as are the rotors 55a within the respective enclosures. Each rotor may include a hollow central region 56a communicating on one side with the adjacent inlet passageway 33a and fixed on its other side to the associated drive shaft 67a. Projecting radially from the hollow central region 56a are a plurality of hollow, tubular spokes or arms 57a each communicating at its inner end with the central rotor region 56a and having its outer or distal end open. The enclosure 40a is configured to extend in adjacent closing relation with respect to the outer end of each rotor arm 57a through approximately one half of its angular rotation, substantially the forward half thereof. The rearward half of rotor-arm rotation is therefore conducted with the distal ends of the arms open toward the outlet openings 47a.

Mounted on the transom 28a adjacent to each enclosure outlet opening 47a is a fluid-control member or reversing scoop 70a. The scoops 70a may each be mounted for generally vertical sliding movement, as in guideways 71a for movement between an upper inoperative positon entirely above the adjacent outlet opening 47a, and a lower, full-reversing position entirely covering the outlet opening and extending below the hull bottom 21a. The upper inoperative position is shown in FIGURES 4 and 5, while the fully lowered position is illustrated in FIGURES 6 and 7. In the latter position, fluid-discharge flow is reversed, see FIGURE 7, to apply reverse thrust to the vessel.

Any suitable operating means may be employed to selectively raise and lower the scoops 70a, such as a cable 74a connected to each scoop and remotely concontrolled by suitable operating handles (not shown).

In operation, sea water is drawn inward through strainers 59a and inlet passageways 33a to the central hollow 56a. of each rotor 55a, whereupon by centrifugal force the sea water is discharged from the rotor arms 57a in the generally rearward direction through enclosure outlet opening 47a. The amount of forward and rearward thrust produced by this liquid discharge may be controlled by positioning of the scoops 70a. Further, the housings 40a may be fixed relative to the hull 20a, as steering may be effected by control of the scoops 70a relative to each other. For example, full-lowered position of the left or port scoop 70a and simultaneous full-raised position of the right or starboard scoop 70a will cause a hard turn to port. If preferred, the relative speeds of rotors 55a may be varied to effect steering action.

Referring now to the additional embodiment of FIG- URES 8-10, there is shown an enclosure or housing gene r ally designated 40b having parallel spaced lower and upper walls 41b and 45b, and an upstanding peripheral side wall 46b extending between the lower and upper walls in the forward region thereof. Thus, the rearward region of enclosure 4% is open, as at 47b, and there provided with flow-straightening vanes 48b. The housing opening 47b is bounded at its opposite sides by extensions 49b and 50b of the side wall 46b.

Interiorly of the housing 40b is a rotor 55b including a hollow central region 56b having a downwardly opening inlet passageway 58b communicating through a central opening 42b in the bottom wall 41b. Projecting radially outward from the central rotor region 56b are a plurality of hollow tubular spokes or arms 57b. The hollow arms communicate at their inner ends with the hollow central rotor region 56b and have their outer ends open.

As best seen in FIGURE 9, the housing 40b is of a generally involute configuration, the side wall 46b having a curvature of generally increasing radius. The rotor 55b is located with its axis generally coincident with that of involute side wall 46b and the radius of each rotor arm 57b is generally equal to or slightly less than the smallest radius of curvature of side wall 46b. Thus, upon counterclockwise rotation of rotor 55b, as indicated by arrow 77b in FIGURE 9, as driven by shaft 67b, the outer or distal ends of rotor arms 57b are eflectively closed only momentarily, if at all, by the radially innermost portion of side wall 46b.

Therefore, in operation of the propulsion device of FIGURES 8-10, the sea water is drawn inward through inlet passageway 58b and substantially continuously discharged from the outer ends of outlet passageways or arms 57b. Thus, centrifugal discharge from the rotor arms 57b occurs forwardly and laterally into the housing 40b, and rearwardly outward through the housing opening 47b. In addition, the rotor arms 57b act as a pump impeller for impelling liquid rearwardly from the interior of housing 40b through the rear housing opening 47b. By this construction the thrust created is the resultant of that produced by 'both centrifugal discharge from the rotor arms and the impelling action of the rotor arms.

As in all of the above-described embodiments of the instant invention, there is a pumping action produced by the propulsion device, it is understood that this pumping action may serve the additional purposes of pumping engine-cooling water, removing bilge water, and the like, by the provision of suitable conduits and valves.

From the foregoing, it is seen that the present invention provides a propulsion device for vehicles which fully accomplishes its intended objects and is well adapted to meet practical conditions of manufacture, installation, maintenance and use.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention and scope of the appended claims.

What is claimed is:

1. In combination, a boat hull having a transom, a well aft in said hull having forward and side walls and having its rear side opening through said transom, said well having a bottom opening communicating with the sea downwardly through the "bottom of said hull, and a propulsion device mounted in said well, said propulsion device comprising a generally horizontally disposed substantially involute-shaped enclosure having a central opening and arranged in said well with its central opening communicating downwardly through the bottom opening of said well, said enclosure having its rear side substantialyl completely open for communication rearwardly overboard through the open rear side of said well and said transom, enclosure-mounting means in said well mounting said enclosure for rotative adjustment about a generally vertical axis through said central opening,

a hollow rotor in said enclosure having an inlet passageway communicating downwardly through said central opening to the sea and having an outlet passageway communicating generally radially outwardly from said inlet passageway, rotor-mounting means mounting said rotor for rotation generally axially of said inlet passageway to move said outlet passageway angularly past said open rear side of said enclosure, drive means connected to said rotor for rotating the latter to pump sea water through said rotor for discharge from said outlet passageway both directly overboard through said rear open side of said enclosure and into said enclosure for subsequent impulsion overboard through the rear open side of said rotor, and deflector means carried by said enclosure in the rear region thereof for directing both the direct outlet discharge and subsequently impelled outlet discharge in substantially parallel flow.

2. The combination according to claim 1, in combination with a flow-reversing scoop mounted for movement between an inoperative position out of covering relation with the open rear side of said enclosure and a fullreversing position in complete covering relation with the rearward opening for reversing a selected portion of the flow of discharged liquid.

3. The combination according to claim 1, the open rear side of said enclosure having a greater area than the cross-sectional area of said outlet passageway.

4. The combination according to claim 1, said enclosure being of increasing transverse dimension along its circumference to accommodate an increasing volume of tangentially moving fluid without back pressure.

5. In combination, a boat hull having a rearward opening, a hollow rotor located in the hull stern having an inlet passageway communicating through the hull to the sea and having an outlet passageway communicating radially outward from said inlet passageway through said rearward opening, mounting means mounting the rotor for rotation generally axially of the inlet passageway to swing the outlet passageway past said rearward opening, drive means connected to said rotor for effecting said rotation thereof to draw sea water into said inlet passageway and centrifugally discharge the sea water through said rearward opening, guide vanes in said opening configured to deflect discharged water into substantial parallelism, said outlet passageway being convergent towards its discharge end for increased discharge velocity, and expansile means for opening said outlet passageway to pass relatively large objects through said outlet passageway without clogging.

References Cited by the Examiner UNITED STATES PATENTS 1,402,719 1/ 1922 Bartlett et al. 2,024,274 12/ 1935 Campini. 2,149,155 2/ 1939 Anderson. 3,052,093 9/ 1962 Kenefick -12 X 3,054,375 9/1962 Neely 11512 3,105,353 10/1963 Schulz 115-12 X FOREIGN PATENTS 564,792 10/ 1923 France.

631,037 9/ 1927 France.

262,066 9/ 1949 Switzerland.

MILTON BUCHLER, Primary Examiner.

FERGUS S. MIDDLETON, Examiner. 

1. IN COMBINATION, A BOAT HULL HAVING A TRANSOM, A WELL AFT IN SAID HULL HAVING FORWARD AND SIDE WALLS AND HAVING ITS REAR SIDE OPENING THROUGH SAID TRANSOM, SAID WELL HAVING A BOTTOM OPENING COMMUNICATING WITH THE SEA DOWNWARDLY THROUGH THE BOTTOM OF SAID HULL, AND A PROPULSION DEVICE MOUNTED IN SAID WELL, SAID PROPULSION DEVICE COMPRISING A GENERALLY HORIZONTALLY DISPOSED SUBSTANTIALLY INVOLUTE-SHAPED ENCLOSURE HAVING A CENTRAL OPENING AND ARRANGED IN SAID WELL WITH ITS CENTRAL OPENING COMMUNICATING DOWNWARDLY THROUGH THE BOTTOM OPENING OF SAID WELL, SAID ENCLOSURE HAVING ITS REAR SIDE SUBSTANTIALLY COMPLETELY OPEN FOR COMMUNICATION REARWARDLY OVERBOARD THROUGH THE OPEN REAR SIDE OF SAID WELL AND SAID TRANSOM, ENCLOSURE-MOUNTING MEANS IN SAID WELL MOUNTING SAID ENCLOSURE FOR ROTATIVE ADJUSTMENT ABOUT A GENERALLY VERTICAL AXIS THROUGH SAID CENTRAL OPENING, A HOLLOW ROTOR IN SAID ENCLOSURE HAVING AN INLET PASSAGEWAY COMMUNICATING DOWNWARDLY THROUGH SAID CENTRAL OPENING TO THE SEA AND HAVING AN OUTLET PASSAGEWAY COMMUNICATING GENERALLY RADIALLY OUTWARDLY FROM SAID INLET PASSAGEWAY, ROTOR-MOUNTING MEANS MOUNTING SAID ROTOR FOR ROTATION GENERALLY AXIALLY OF SAID INLET PASSAGEWAY TO MOVE SAID OUTLET PASSAGEWAY ANGULARLY PAST SAID OPEN REAR SIDE OF SAID ENCLOSURE, DRIVE MEANS CONNECTED TO SAID ROTOR FOR ROTATING THE LATTER TO PUMP SEA WATER THROUGH SAID ROTOR FOR DISCHARGE FROM SAID OUTLET PASSAGEWAY BOTH DIRECTLY OVERBOARD THROUGH SAID REAR OPEN SIDE OF SAID ENCLOSURE AND INTO SAID ENCLOSURE FOR SUBSEQUENT IMPULSION OVERBOARD THROUGH THE REAR OPEN SIDE OF SAID ROTOR, AND DEFLECTOR MEANS CARRIED BY SAID ENCLOSURE IN THE REAR REGION THEREOF FOR DIRECTING BOTH THE DIRECT OUTLET DISCHARGE AND SUBSEQUENTLY IMPELLED OUTLET DISCHARGE IN SUBSTANTIALLY PARALLEL FLOW. 